"Californians pay on average a total of 15.2 cents per kilowatt hour for electricity, or about 50 percent above the national average, according to the U.S. Department of Energy. On the other hand, Californians use roughly half as much electricity per capita as the average American, according to California Energy Commission data."

"Borenstein said the biggest obstacle to hitting 100 percent will be storage. Natural gas-fired plants, which account for 33 percent of the state’s electricity, can be ramped up and down as demand fluctuates. But wind power can only be generated when it’s windy; solar power only works when it’s sunny. They can’t be stored up, and sometimes supply doesn’t conveniently sync up with demand."

"For instance, Borenstein said wind generation is most plentiful at night — when skies tend to be windier — but that’s when electricity consumption drops. Solar matches up better, but there are still times when demand is high but supply is scarce, such as early evening."

"That doesn’t mean going all-renewable will be impossible, though. Borenstein said California’s 'knowledge economy' is the perfect laboratory for investing and perfecting new technologies that could solve the problem."

"'We could get new technologies for storage that we haven’t even thought of yet,' he said. 'That’s exactly what California should be doing, and is good at.'"

"In that sense, he said the real benefit of SB 100 is as a spur to innovation. California barely accounts for 1 percent of the world’s greenhouse gases; by itself the state can’t make a real dent in global warming. But if the state can master the technological challenges of an all-renewable grid, it can show the way for other states and countries.

“'If it turns out we figure out ways to do this cost effectively, that is going to ripple out ... and move the rest of the world toward getting off fossil fuels,' Borenstein said."